'This code segment implements the IContainer interface. The code segment
'containing the implementation of ISite and IComponent can be found in the documentation
'for those interfaces.
'Implement the LibraryContainer using the IContainer interface.
Class LibraryContainer
Implements IContainer
Private m_bookList As ArrayList
Public Sub New()
m_bookList = New ArrayList()
End Sub
Public Sub Add(ByVal book As IComponent) Implements IContainer.Add
'The book will be added without creation of the ISite object.
m_bookList.Add(book)
End Sub
Public Sub Add(ByVal book As IComponent, ByVal ISNDNNum As String) Implements IContainer.Add
Dim i As Integer
Dim curObj As IComponent
For i = 0 To m_bookList.Count - 1
curObj = CType(m_bookList(i), IComponent)
If curObj.Site IsNot Nothing Then
If (curObj.Site.Name.Equals(ISNDNNum)) Then
Throw New ArgumentException("The ISBN number already exists in the container")
End If
End If
Next i
Dim data As ISBNSite = New ISBNSite(Me, book)
data.Name = ISNDNNum
book.Site = data
m_bookList.Add(book)
End Sub
Public Sub Remove(ByVal book As IComponent) Implements IContainer.Remove
Dim i As Integer
Dim curComp As BookComponent = CType(book, BookComponent)
For i = 0 To m_bookList.Count - 1
If (curComp.Equals(m_bookList(i)) = True) Then
m_bookList.RemoveAt(i)
Exit For
End If
Next i
End Sub
Public ReadOnly Property Components() As ComponentCollection Implements IContainer.Components
Get
Dim datalist(m_bookList.Count - 1) As IComponent
m_bookList.CopyTo(datalist)
Return New ComponentCollection(datalist)
End Get
End Property
Public Overridable Sub Dispose() Implements IDisposable.Dispose
Dim i As Integer
For i = 0 To m_bookList.Count - 1
Dim curObj As IComponent = CType(m_bookList(i), IComponent)
curObj.Dispose()
Next i
m_bookList.Clear()
End Sub
Public Shared Sub Main()
Dim cntrExmpl As LibraryContainer = New LibraryContainer()
Try
Dim book1 As BookComponent = New BookComponent("Wizard's First Rule", "Terry Gooodkind")
cntrExmpl.Add(book1, "0812548051")
Dim book2 As BookComponent = New BookComponent("Stone of Tears", "Terry Gooodkind")
cntrExmpl.Add(book2, "0812548094")
Dim book3 As BookComponent = New BookComponent("Blood of the Fold", "Terry Gooodkind")
cntrExmpl.Add(book3, "0812551478")
Dim book4 As BookComponent = New BookComponent("The Soul of the Fire", "Terry Gooodkind")
'This will generate an exception, because the ISBN already exists in the container.
cntrExmpl.Add(book4, "0812551478")
Catch e As ArgumentException
Console.WriteLine("Unable to add books: " + e.Message)
End Try
Dim datalist As ComponentCollection = cntrExmpl.Components
Dim denum As IEnumerator = datalist.GetEnumerator()
While (denum.MoveNext())
Dim cmp As BookComponent = CType(denum.Current, BookComponent)
Console.WriteLine("Book Title: " + cmp.Title)
Console.WriteLine("Book Author: " + cmp.Author)
Console.WriteLine("Book ISBN: " + cmp.Site.Name)
End While
End Sub
End Class

Comentarios

Los contenedores son objetos que encapsulan y realizan un seguimiento de cero o más componentes.Containers are objects that encapsulate and track zero or more components.En este contexto, la contención se refiere a la contención lógica, no a la contención visual.In this context, containment refers to logical containment, not visual containment.Puede usar componentes y contenedores en diversos escenarios, incluidos escenarios visuales y no visuales.You can use components and containers in a variety of scenarios, including scenarios that are both visual and not visual.

Métodos

Agrega la IComponent especificada a IContainer al final de la lista, y le asigna un nombre al componente.Adds the specified IComponent to the IContainer at the end of the list, and assigns a name to the component.